#include<iostream>
#include<cstdio>
#include<algorithm>

using namespace std;

using LL = long long;

int main()
{
    LL n;
    cin >> n;
    n /= 1000;
    n %= 86400;
    int h = n / 3600;
    n %= 3600;
    int m = n / 60;
    int s = n % 60;
    printf("%02d:%02d:%02d\n", h, m, s);
    return 0;
}